OOAK Table Tennis Forum

I found it hard to find a suitable topic title to this so if you think of something better let me know and I'll try get amended.

My question is who determines the sponge hardness for a new rubber line. Do you think the brand such as Donic and Tibhar come with a specific hardness of rubber such as 40 or 45 etc and relay this to the manufacturer? Or do you think they might request a type of hardness such as medium soft so when it comes back and its 42.5, thats just accepted. Baracuda is 42.5 apparently. Was this determined by Donic or did the sponge that came back from the designer/manufacturer sit at 42.5 and if it had of come back 43 or 44, would still have been ok.

When there is no hardness in the brand name, perhaps this is the case. Take for example the new Tibhar Aurus Prime and Aurus Select, said to be 47 and 42 degress respectively. Was this requested by Tibhar or did they just describe characteristics and when it came back as 47 and 42 that was good enough and would have been just as good if they were perhaps 48 and 41.

Now we get onto the Rasanter series where they have 37, 42, 47, 50. Its interesting that the first 3 levels go up in 5 degrees then the last is 3 degress. Would Andro have requested this or once again, was that defined by the sponge created and could just have easily now be titled R36, R41, R48, R51?

A sceptic in me would even perhaps suggest that maybe the actual hardnesses may in fact be more like the second lot of numbers as who is likely to tell anyway.

I'm not sure how this works. I guess I'm simply asking whether manufacturers, usually ESN have the skill to come up with an exact hardness and whether if requested they could come up with the same rubber in say 42, 43, 44, 45, 46 etc hardness sponge, or as I've suggested do they just pump something out that is close enough and the brand runs with it?

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Donic Waldner Senso V1,FH Baracuda Big Slam 2.0mm ,BH Victas Triple Regular 2.0mm

I would expect that the brands would specify what hardness they want, and ESN will manufacturer to that hardness, within a certain tolerance of course, which may be something like +/- 1deg.

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Not that it really matters but when Tibhar got 47 for Aurus Prime, is that what they requested or close enough.

I'd say Rasanter was requested at 37, 42, 47, 50 but wonder if that's what they are or as you say actually +/- 1 degree.

Maybe Rasanter R42 is actually Rasanter R43?

Thinking of getting a durometer for $20-$30 dollars just for fun, not sure how accurate it will be.

Sent from my SM-T210 using Tapatalk

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Donic Waldner Senso V1,FH Baracuda Big Slam 2.0mm ,BH Victas Triple Regular 2.0mm

As the overall hardness or feel of the rubber depends on the marriage of both the top sheet and the sponge I reckon the companies such as Tibhar request samples in all combinations of top sheet and sponge and then test them all until they find the right combinations. They then order the combination, which is why sponge ratings are a bit all over the place and not a true indicator of the final rubber hardness.

For example Xiom Omega Pro and Omega Euro are supposed to be very close in performance and feel with Pro possibly having a slightly harder sponge and softer top sheet whilst Euro a softer sponge and harder top sheet.

http://blog.tabletennis11.com/xiom-omeg ... ur-reviews

I suspect that if you measured the sponge hardness on ten different batches of the same rubber made several months apart, you'd find more variation than you'd think you'd have. It seems to be true for weight, even with such rubbers as Tenergy, I'll bet variations in hardness are at least as large. And Chinese sheets would be worse - you sometimes see HUGE weight variations there. With the Chinese I'll bet they simply test each cake as it comes out of the steamer and throw it in the appropriate bin.

Iskandar

I've looked in to this too. It won't be accurate. Most people suggest Shore A Durometer designed for soft rubbers and sponge but for you to get an accurate reading others prefer to use something like Shore A00 which doesn't use a point to measure hardness. Regardless, to get an accurate reading you'd need a certain thickness of sponge, a thickness which is much more than you'd get with table tennis rubbers.

The best you could do would be to get "comparative" readings which is what I think haggisv does when people send him off cuts of rubbers to measure their hardness.

Hmmm!!!

https://www.aliexpress.com/item/Shore-D ... 83222.html

https://www.aliexpress.com/item/A-Type- ... 43916.html

Mechanical ones for less then USD15, digital ones for USD25 or so. I don't think you'd need to worry too much about calibration (there are various objects you can try them on, e.g. skateboard wheels and car tires). Problem is, yes, our rubber sheets aren't anywhere near thick enough for valid measurements.

https://en.wikipedia.org/wiki/Shore_durometer

Iskandar

[QUOTE=Sedis] <span style=": rgb251, 251, 253;">Brand: Stiga</span><br style=": rgb251, 251, 253;"><span style=": rgb251, 251, 253;">Rubber ID/Model: Airoc Astro S</span><br style=": rgb251, 251, 253;"><span style=": rgb251, 251, 253;">Thickness: 2.1</span><br style=": rgb251, 251, 253;"><span style=": rgb251, 251, 253;">Colour: Red</span><br style=": rgb251, 251, 253;"><span style=": rgb251, 251, 253;">Uncut Mass: 64g</span><br style=": rgb251, 251, 253;"><span style=": rgb251, 251, 253;">Length: 168</span><br style=": rgb251, 251, 253;"><span style=": rgb251, 251, 253;">Width: 168</span>[DIV]<span style=": rgb251, 251, 253;">Measured sponge hardness: 42</span><span style="color: rgb84, 84, 84; font-family: arial, sans-serif; font-size: small;">°</span><span style="color: rgb84, 84, 84; font-family: arial, sans-serif; font-size: small;"> </span><span style=": rgb251, 251, 253;">Shore O</span>[/DIV]
[/QUOTE]
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Hi, Sedis

It's great to obtain the Hardness actual numbers from tester's hand directly.. . So good you able to handle the Shore device and able to make measurements properly, indeed.
Yes, we really need all the tribology scientifical data of each rubber in the LARC list, and we urge all the rubber users to do a hardness test on the rubber sample you can reach to.

Dear Fellow Boffin Sedis.,
Your given measurements of sponge hardness is of real value, indeed. Yes, we gonna incorporate your most useful information into our Rubber Hardness Chart and the Sheet Of Rubber Mass as well.

YOURS GRATEFULLY..

https://tabletennis-reviews.com/referen ... ess-table/